This proposal seeks to elucidate the relationship between local crevicular fluid prostaglandin E (CF-PGE) concentrations and periodontal disease activity. PGE is a biochemical mediator of inflammation that can elicit many of the pathological changes that occur in periodontal disease such as vasodilation, increased vascular permeability, edema, decreased collagen synthesis and bone resorption. Recent studies in our laboratory have demonstrated that CF-PGE levels can be markedly elevated in some periodontal sites in patients with advanced periodontal desease. It is hypothesized that elevated CF-PGE levels may be a direct reflection of periodontal destruction. This proposal outlines the implementation of a longitudinal study to determine if crevicular fluid PGE levels are elevated during periods of human periodontal attachment loss. It is anticipated that this non-invasive, site-specific monitoring technique will provide an objective assessment of periodontal desease activity. Patients with advanced periodontal disease will be monitored longitudianlly every two months to collect crevicular fluid and perform clinical measurements at each monitoring site. Clinical measurements will include assessments of gingival erythema, edema, suppuration, bleeding on probing, pain on probing, attachment level and darkfield enumeration of ten morphological classes of subgingival flora. Patients will be monitored until a periodontal site undergoes a small but statistically significant loss of attachment. Each patient will serve as their own control by comparing CF-PGE levels at sites which show significant loss of attachment to CF-PGE levels at sites which do not lose attachment. As soon as disease activity is detected, routine periodontal surgical therapy will be instituted, retaining tissues for PGE2 quantitation. Tissue PGE2 levels at the active site will be compared to PGE2 levels in tissues from adjacent non active sites. The interrelationships between all clinical and laboratory measurements will be determined.